Process for the coloration of cellulose textile fibers



.fibers with improved fastness properties.

United States Patent Delaware No Drawing. Filed Aug. 19, 1960, Ser. No.50,593

8 Claims. (Cl. 8-18) This invention relates to the coloration of textilefibers and more particularly to a method for producing colored textilefibers with improved fastness properties and the like.

A great number of dyeing, printing and other processes for thecoloration of textile fibers is known, but most such processes sufferthe disadvantage of limited operability with respect to the range oftypes of fibers and/or dyestuffs employed. Another disadvantage commonto anumber of such processes resides in the insufiiciently improvedfastness properties of the colored products produced thereby.

It is an object of this invention to provide a process for thecoloration of textile fibers which will not be subject to one or more ofthe above disadvantages. Another object of this invention is theprovision of a coloring process operative with a wide range of dyestuffsand applicable to a wide range of types of textile fibers. Still anotherobject of this invention is the provision of a process for theproduction of colored textile Other objects and advantages will appearas the description proceeds.

The attainment of the above objects is made possible by the presentprocess 'which comprises treating textile fibers with an aqueous mediumcontaining a soluble dyestulf, a soluble acid-curing aminoplast and asoluble acid-reacting catalyst for the aminoplast, drying and thenheating the treated and dried fibers at a temperature of at least 350 F.The process of this invention enables the production of colored textilefibers having surprisingly improved fastness to washing, chlorine,alkaline and acid perspiration and/or crocking. The process also resultsin less wash-down after the heating or curing step as compared withprior processes, thereby minimizing loss of dyestulf and aminoplast andthe duration and/or number of rinsing operations. In addition, theprocess enables the coloration of a Wide range of different types oftextile fibers with diverse types of dyestuffs including those which arenot substantive to the fiber whereby colored products may be obtained inany desired shade.

Another unexpected advantage of this process is the fact that compoundshades can be made with dissimilar classes of dyestuffs such as directcotton dyes, acid wool dyes, premetallized acid dyes, and premetallizedneutral dyeing sulfonamide azo dyes, which is not possible with standarddyeing procedures.

In US. Patent No. 2,169,546 there is disclosed a process for coloringtextile fibers by treating the fibers with an aminotriazinealdehydecondensation product and a soluble dyestnif simultaneously or insuccession in either order followed by hardening the condensationproduct as by heating to temperatures up to 120 C.

" 3,142,529 Ce Patented July 28, 1964 (248 F.). This process has,however, been found to yield colored products with insufiicientlyimproved fastness properties. This patent refers to US. Patent No.2,310,004 (Serial No. 68,355) for a disclosure of operativeaminotriazine-aldehyde condensation products. Such condensation productsare also employed in the textile treating process described and claimedin U.S. Patent No. 2,191,362 which discloses that in hardening suchcondensation products on the fiber, relatively low curing temperaturesare desired to minimize damage to the fiber and for economic reasons.The latter patent in fact discloses that increasing the curingtemperature from C. to C. yields no improvement in fastness to washing.It was accordingly highly surprising to find that when thesecondensation products and other similar acid-curing aminoplasts areapplied to textile fibers simultaneously with soluble dyestuffs and thetreated fibers subjected to curing temperatures of at least 350 F., theresulting products have unexpectedly improved fastness to washing andthe like.

The mechanism by which the improved results of this process is attainedis not definitely understood although it is hypothesized that there isinvolved an improved bonding or reaction between the aminoplast and thefiber and/or between the dyestuff and the aminoplast.

The acid-curing aminoplasts operative in the present process are wellknown in the art and may be defined as water-soluble or readily waterdispersible condensation products of amino or amido compounds withaldehydes in monomeric or partially polymerized form having the inherentproperty of curing under the influences of heat and acidic conditions toa hardened, insoluble state. The preferred amino or amido compounds foruse in preparing these aminoplasts are aminotriazines and triazones. Asrepresentative of these and other amino or amido compounds which may beemployed in forming these aminoplasts, there may be mentioned triazonessuch as N-lower alkyl (e.g. methyl, ethyl,etc.)-N",N"'-dimethyloltriazine and triazines and aminotriazines such asmelam, melem, melon, formoguanine, aminotriazines wherein one or twoamino groups are substituted by hydroxy, halogen, alkyl, aryl or aralkylgroups such as ammeline, ammelide, 2-chloro-4,6-diamino-1,3,5-triazine,2-(p-hydroxyphenyl)-4,6-diamino-1,3,5-triazine,2-pheny1-4-amino-6-hydroxy-1,3,5-triazine, and acetoguanamine,aminotriazines wherein one or more amino-hydrogen atoms are substitutedby amino, alkyl, aryl or aralkyl groups such as2,4,6-trihydrazino-1,3,5-triazine, N-dimethyl melamine, N,N",N"-triethylmelamine, N',N", N"-triphenyl melamine, propionoguanamine, N-ethyl-2-.acetoguanamine and the like.

Formaldehyde or compounds yielding formaldehyde such asparaformaldehyde, trioxymethylene and hexamethylenetetramine, arepreferred as the aldehyde for reaction with the amino or amidocompounds. Other aliphatic, aromatic and heterocyclic aldehydes may alsobe employed such as acetaldehyde, paraldehyde, crotonaldehyde, acrolein,propionaldehyde, butyraldehyde, methacrolein, benzaldehyde, furfural,and the like. One or a plurality of moles of the aldehyde are condensedwith one mole of the amino or amido compound depending upon the natureof said compound and the nature of the condensation product desired.This condensation may be assisted by an alkaline or acid catalyst inknown manner and the condensation may be carried out so as to produce amonomer or a water soluble polymer. It is to be understood that the termwater soluble condensation product employed herein covers both themonomeric condensation product and water soluble or readily waterdispersible polymers thereof, in addition to derivatives andmodifications thereof produced by reaction of the condensation productwith alcohols such as methyl and ethyl alcohol, amides, toluenesulfonamides, and the like. A preferred type of aminoplast is disclosedin U.S. Patent No. 2,609,- 307. These aminoplasts are cationiccolloidally dispersed aminotriazine-aldehyde condensation products whichare highly elfective in the process of this invention. A number of otherwater soluble aminoplasts of the type defined above as operative in thepresent process have been disclosed in patents and other publications.

As the acid reacting catalyst for use in the instant process, thoseparticularly preferred are the latent catalysts which liberate acid whenheated in contact with textile fibers at a temperature of at least 350F. Such catalysts preferably do not produce highly acidic solutions whendissolved in the aqueous treating medium but liberate the desired amountof acid when subjected to curing temperatures of 350 F. in the presenceof the textile fiber. A particularly preferred group of latent acidreacting catalysts are those disclosed in U.S. Patent No. 2,467,160.This type of catalyst may be defined as a hydroxy amine salt in which aprimary amino. group is on a tertiary aliphatic carbon atom adjacent toat least one carbon atom to which an alcoholic hydroxy group is attachedand the remainder of the molecule consists of hydrocarbon radicals takenfrom the group consisting of alkyl and aryl. Examples of such catalystsare salts of Z-amino-Z-methyll-propanol,2-rnethyl-2-amino-l,3-propanediol, tris(hydroxymethyl)aminomethane, 2phenyl-Z-amino-l-propanol, 2-methyl2-amino-l-pentanol, etc., with aninorganic or organic, saturated or unsaturated, monobasic or polybasicacid such as hydrochloric, phosphoric, sulfuric, sultamic, sulfonic,acetic, chloroacetic, propionic, butyric, acrylic, cinnamic, benzoic,phthalic, boric, maleic, citric, formic, tartaric, oxalic, sulfocyanic,hydrobromic, hydrofluoric, hydroiodic, nitric, selenic, chromic,valeric, caproic, methacrylic, melonic, succinic, glutari, adipic,lactic, malic, fumaric, itaconic, citraonic, salicylic, etc. Thesecatalysts are preferred because of their resistance to preliminaryhydrolysis and decomposition in the aqueous treating medium, theirstabilizing effect upon the aminoplast and the textile fiber, and theirability to liberate the desired quantities of acid at the curingtemperatures employed herein without a concurrent liberation of ammoniaor other odoriferous by-products.

Another, though less preferred group of latent catalysts are the saltsof the above acids with ammonia or other organic amines or amino mcoholssuch as methylamine, dimethylamine, hydrazine, and its derivatives,cyclohexylamine and derivatives, mono-, di-, and triethanolarnines,-propanolamines, -isopropanolamines, and -butanolamines, choline,isocholine, neurine, 1-amino-4-butanol, diacetone alkamine, and thelike.

Other acid reacting catalysts which may be employed are the metal saltssuch as zinc, aluminum and magnesium nitrates and chlorides in additionto the above mentioned free acids. These catalysts are, however, leastpreferred because of their tendency to damage the textile fiber and/ orthe dyestuff in the treating medium.

Any dyestuff may be employed in this process which is soluble (includingreadily water dispersible) in the aqueous treating medium. Suchdyestuffs are well known in the art and include such types as aciddyestuffs, direct dyestuffs, basic dyestuffs, neutral and acid-dyeingpre- Type Colour Index No. or Name, 2nd Edition Direct (phthalocyanine).Direst (disazo).

Acid anthraquiuone.

o. Metailized monoazo.

new. Direct (disazo) OH i -Q It will also be understood that the aqueoustreating medium may contain any other desired textile assistants orfunctional agents such as plasticizers, softeners, mildewproofingagents, moth-proofing agents, water repelling agents, and the like. Theaqueous treating medium may be prepared by mixing the components in anyorder. It is, however, preferred to first dissolve the dyestuff in aminimum amount of warm or hot water, if desired with the assistance of awetting agent which may be nonionic, anionic or cationic of known typedepending upon the character of the dyestufif. This solution is thencooled to room temperature or the like and the acid-curing aminoplastadded with vigorous agitation. The cooling step is desirable to preventpremature polymerization of the aminoplast. The catalyst is then addedto the treating medium.

In preparing the aqueous treating medium, the concentration of dyestutfwill depend upon whether a batch or continuous process is employed,proportion of solution take-up by the textile fibers, etc. The presentprocess lends itself admirably to continuous, high speed dyeing andprinting operations which have become increasingly important in thecommercial field. In general, the treating medium should contain fromabout '3 to 20% by weight of the aminoplast, the higher proportions inthis range yielding products with increased stiffness. Higher amounts ofaminoplast may of course be employed if a very stiff product is desired.About 2 to 15% of the acid reacting catalyst is employed based on theweight of the aminoplast under ordinary conditions. Since in some casesthe aqueous medium will be at a pH of more than 7 in order to solubilizecertain types of dyestuffs, increased amounts of catalyst in the upperpart of said range and in excess thereof may be employed to compensatefor such alkalinity. Ordinarily, the aqueous medium is preferablyapplied at a neutral or slightly acid pH. In general, an amount ofdyestuif is employed in the aqueous treating medium which will depositupon the textile fiber about 0.2 to 5% of dyestutf depending upon thedepth of shade desired, etc.

When the aqueous medium is applied by an impregnating or paddingprocess, there is produced, simultaneously with a dyeing o1- colorationof the textile fiber, a highly desirably crease-resistant and/ orwash-and-wear finish.

,The present process accordingly enables the attainment of highlyefficient and economic operation in that the usual separate dyeing andcrease-proofing treatments are combined in one operation. The treatingmedium may of course by sprayed on the textile fiber to produce surfaceeffect which may be local or overall.

In the preferred form of the invention wherein the textile fibers arecontinuously padded with the treating medium, excess medium removed andthe treated fibers dried and cured, the removal of excess may be carriedout in known manner by a squeezing step, use of centrifugal force, etc.In the usual case, the textile fibers after the padding and excessremoval operations, will retain about 60 to 80% of treating medium byweight of the fiber, although amounts of 40 to 200% may be allowed toremain under certain conditions.

If desired, the treating medium may be applied by printing which may beoverall or in local areas to achieve ornamental effects. In suchcircumstances, the medium should be thickened in known manner, it beingpreferred to avoid the use of hydroxylated thickeners which may reactwith the aminoplast during the subsequent curing operation. A preferredmethod of thickening is the known use of an oil-in-Water emulsionwherein a volatile liquid such as Varsol or mineral spirits isemulsified in the water phase containing the aminoplast, dyestuif andcatalyst.

Following the application of the treating medium to the textile fibers,the treated fibers are dried at a temperature ranging from roomtemperature up to about 212 F. or the like after which the dried fibersare subjected to a curing or dry heat treatment at a temperature of atleast 350 F. for a sufficient length of time to achieve the desiredhardening and insolubilization of the aminoplast. Temperatures of up to450 F. may be employed, the duration of curing varying inversely withthe temperature. Durations of curing may range from 5 minutes or morefor temperatures in the lower part of the curing range to 30 seconds orless at curing temperatures approaching 450 F.

The maximum curing temperature which may be employed in any particularinstance to achieve the desired hardening and insolubilization withoutdamage to the fiber can be readily ascertained by routineexperimentation and will of course depend upon the nature of the fiber,the duration of curing, etc.

It will be understood that the relatively elevated curing temperaturesemployed in the present process are essential and critical for theattainment of the desired improved fastness properties and the like,lower curing temperatures having been found to yield noticeably inferiorfastness properties.

Following the curing step, the fibers are in known manner subjected to arinsing and/ or soaping to remove undesirable by-products, unfixedmaterial, and the like. Generally, a water rinse at room temperature upto 180 F. or so followed by an alkaline soaping with soda ash and soapor synthetic detergent will be found sufiicient. Any synthetic detergentmay be employed such as for example nonionic surface active agents asexemplified by the condensation product of nonyl phenol with to moles ofethylene oxide, anionic surface active agents such as sodium N-methyltauride and the like, and cationic surface active agents. As has beenreferred to above, the present process results in improved fixation ofdyestulf and aminoplast and accordingly less loss of treating materialin this wash down step and/or a more rapid wash down.

The process of this invention is applicable to textile fibers of anyform and chemical constitution. The fibers may be in staple orcontinuous filament form and fabricated as yarns, slubbings, warps,Woven and unwoven fabrics, etc. When applied to felted or unwovenstructures, a simultaneous cementing or bonding of the fibers may beobtained, which effect may be enhanced if desired by an increase in theproportion of aminoplast in the aqueous treating medium.

The process of this invention has been found to be highly elfective forthe coloration of cellulose fibers such as cotton, linen, and the like.As pointed out above, it is theorized that a reaction may take placebetween the dyed aminoplast and the hydroxyl groups in the cellulose.The process is, however, also applicable to other textile fibersregardless of their chemical nature, including polyesters,polyacrylonitriles, and other fibers containing a reactive hydrogen atomsuch as natural and synthetic polyamides including wool, silk, casein,zein, nylon and polyurethane.

The following examples in which parts and proportions are by weightunless otherwise indicated, are only illustrative of the presentinvention and are not to be regarded as limitative.

EXAMPLE 1 A. 2 grams of Sulfo Rhodamine B extra (Colour Index No. 748,1st edition) are dissolved with the aid of heat in 42 ml.,of water and 5ml. ethanol. This solution is cooled and introduced with agitation intoa solution of 15 grams of a water soluble methylol melamine condensationproduct, produced as described in Example 1 of US. Patent No. 2,169,546,in 30 ml. of Water and 1 ml. of 28% ammonia solution. 5 ml. of 50%aqueous ammonium sulfocyanide is then added to the resultingdyestufi-aminoplast solution. This aqueous bath, at a pH of about 6.5,is employed for padding a bleached cotton fabric after which the paddedfabric is squeezed to leave about 75% of the treating medium on theweight of the fiber (owf. The treated fiber is then dried and cured for4 minutes at 248 F. C.). The heat treated fabric is then rinsed withcold water and washed with an 0.3% solution of sodium N-methyl tauride,made alkaline with soda ash, at a temperature of about F. The resultingdyeing is subjected to AATCC Wash Tests Nos. 3 and 3A, chlorinefastness, fastness to acid and alkaline perspiration crocking.

B. The procedure of part A above is repeated except that the padded,squeezed and dried fabric is subjected to heat treatment at 350 F. for 3minutes instead of for 4 minutes at 248 F.

Dyeing B is found to have unexpectedly better fastness to washing,chlorine, acid and alkaline perspiration and crocking as compared withdyeing A. Further, there is noticeably less wash-down of the curedfabric following the procedure of part B as compared with part A,

EXAMPLE 2 The procedures of parts A and B of Example 1 are repeatedexcept that 2.5 grams of dibasic ammonium phosphate are employed insteadof the 5 ml. of 50% aqueous ammonium sulfocyanide. With this catalyst,dyeing B exhibits a much greater improvement in fastness propertiesrelative to dyeing A.

EXAMPLE 3 The procedures of parts A and B of Example 1 are repeatedexcept that the methylol melamine condensation product there employed issubstituted by the Resin A described in column 5 of US. Patent No.2,609,307. This resin is a methylated trimethylol melamine (trimethoxy-2 methyl melamine). Dyeing B exhibits similarly improved fastnessproperties as compared with dyeing A.

EXAMPLE 4 The procedures of parts A and B of Example 3 are repeatedexcept that the amonium sulfocyanide is substituted by the hydrochloricacid salt of 2-arnino-2-methyl-1- propanol. Dyeing B exhibits an evengreater improvement in fastness properties as compared with dyeing A, inaddition to a noticeable relative absence of odor in the curing processand the resultant dyeing.

EXAMPLE 5 The procedure of each of Examples 1 to 4 are repeated exceptthat in each example the Sulfo Rhodamine B Extra is substituted byFormyl Violet S4BA (Colour Index No. 698, 1st edition). In each case,dyeing B exhibits unexpectedly improved fastness properties and lesswash-down as compared with dyeing A.

EXAMPLE 6 2 oz. of dyestuff CI. 29065 (2nd edition) are dissolved withthe aid of heat and 1 oz. of sodium alkyl naphthalene sulfonate in aminimum amount of water. The solution is cooled and mixed with a 35%solution containing 12 oz. of the resin employed in Example 3. Thesolution is made up to 1 gallon with water and 2 oz. of the catalystemployed in Example 4 are added. A bleached cotton fabric is paddedthrough the resulting aqueous treating medium, squeezed, dried, curedfor 3 minutes at 360 F., rinsed with cold water and soaked at the boilfor 2 minutes with a 2% solution of the condensation product of laurylalcohol with 8 moles of ethylene oxide made alkaline with soda ash. Theresulting dyeing has good to excellent fastnses to washing, acid andalkaline perspiration.

EXAMPLE 7 2 oz. of dyestuff CI. 23630 (2nd edition) are dissolved withthe aid of heat and 0.2 oz. of the condensation product of nonyl phenolwith 6 moles of ethylene oxide in a minimum amount of water. Thesolution is cooled and mixed with 16 oz. of the resin employed inExample 3 after which the solution is made up to 1 gallon with water,the pH adjusted from 8.5 to 6.5 with 0.6 ml. of aqueous formic acid and2 oz. of the catalyst of Example 4A added. A bleached cotton fabric ispadded through the resulting aqueous medium squeezed, dried, cured for 3minutes at 350 F., rinsed with cold water and soaped. The resultingdyeing has good to excellent fastness to AATCC Wash Tests 3 and 3A,chlorine, and acid and alkaline perspiration.

EXAMPLES 8 THROUGH 16 In the following examples the dyestuffs listed inthe table below are employed in the following dyeing procedure. 2 g. ofthe selected dyestufi are dissolved in 80 ml. of hot water, (temp. about140 F.): 1 ml. of sodium alkyl naphthalene sulfonate (Nekal NF) wettingagent is then added. The solution is then permitted to cool down toabout 90 to 100 F. and there is then added 16.0 g. of the resin ofExample 3 and 1.5 g. of the hydrochloric acid salt of2-amino-2-methyl-l-propanol catalyst. Water is then added to bring thetotal volume of the solution up to 133 ml. A bleached cotton fabric isthen padded S in this dyebath at to F., then dried and finally cured at360 F. for 3 minutes. The heat treated fabric is then soaked at the boilfor 1 to 2 minutes and dried. The following table indicates theresultant dyeings also:

Table Example Dyestufi, Colour Index Remarks (2nd Edition) 8 74180Bright greenish blue, excellent wet fastness.

9 19010 Bright yellow, excellent wet fastness, goodlight fastness.

1O 15045 Violet blue, excellent light and wash iastness.

11 Cobalt complex of Dye- Excellent bordeaux color, stufi 01.15675. goodwash and light Iastness. 12 Chromium complex of the Red orangeofexeellent wash monoazo dye from 2- and light tastness. amino-l-phenoll-sulfonamide diazotized and coupled to 3-methyl-1- phenyl-5-pyrazolone.13 Cobalt complex of the dye- Deep brown, good wash and stud obtainedfrom 2- light Iastness. amino-4-nitrophenol diazotized and coupled to 3methyl 1 (U1 suliamylphenyl)-5-pyrazolone. 14 0.1. 62160 Blue violet,excellent wash and light fastness.

Brilliant blue, excellent wash and light iastness.

0.1. 62550 Bright green, excellent wash and light l'astness.

This invention has been disclosed with respect to certain preferredembodiments and various modifications and variations thereof will becomeobvious to persons skilled in the art. It is understood that suchmodifications and variations are to be included within the spirit andscope of this invention.

We claim:

1. A process for the coloration of cellulose textile fibers comprisingtreating the fibers with an aqueous medium containing a solublenon-fiber reactive dyestutf, a soluble acid-curing aminoplast and asoluble acid-reacting catalyst for the aminoplast, said aminoplast beinga soluble condensation product of an aldehyde with a member of the groupconsisting of aminotriazines and triazones, drying and then heating thetreated and dried fibers at a temperature of at least 350 F.

2. A process as defined in claim 1 wherein the aminoplast is a methylolmelamine.

3. A process as defined in claim 1 wherein the aminoplast is atrimethoxymethyl melamine.

4. A process as defined in claim 1 wherein the aminoplast is a dimethyltetramethylol melamine.

5. A process as defined in claim 1 wherein the aminoplast is an N-loweralkyl-N",N"'-dimethylol triazone.

6. A process as defined in claim 1 wherein the catalyst is a latentcatalyst which liberates acid when heated in contact with textile fibersat a temperature of at least 350 F.

7. A process as defined in claim 6 wherein the catalyst is an ammoniumsalt.

8. A process as defined in claim 6 wherein the catalyst is a hydroxyamine salt in which a primary amino group is on a tertiary aliphaticcarbon atom adjacent to at least one carbon atom to which an alcoholichydroxy group is attached and the remainder of the molecule consists ofhydrocarbon radicals taken from the group consisting of alkyl and aryl.

(References on following page) 9 10 References Cited in the file of thispatent FOREIGN PATENTS UNITED STATES PATENTS 8 ,505 reat Britain Aug.31, 1960 OTHER REFERENCES z l et a1 Sept'211937 5 Broden et al.: Amer.Dyestufi Reporter, January 4,

rdmer et a1 Aug. 15, 1939 1954, pages P6 P13 wfdmer at 1940 Ward:Chemistry and Chemical Technology Cotton, wldmer fit 1943 1955, p. 5 10,Interscience Publishers, Inc., NY. (Copy in Schreiber et a1. Mar. 4,1947 P.O.S.L.).

Scott A 12, 1949 10 Derwent: Belgian Patent Report No. 54A, June 30,

Fluck et al. Sept, 2, 1952 1959, P ge C Belgian Patent No. 573,126.

1. A PROCESS FOR THE COLORATION OF CELLULOSE TEXTILE FIBERS COMPRISINGTREATING THE FIBERS WITH AN AQUEOUS MEDIUM CONTAINING A SOLUBLENON-FIBER REACTIVE DYESTUFF, A SOLUBLE ACID-CURING AMINOPLAST AND ASOLUBLE ACID-RACTING CATALYST FOR THE AMINOPLAST, SAID AMINOPLAST BEINGA SOLUBLE CONDENSATION PRODUCT OF AN ALDEHYDE WITH A MEMBER OF THE GROUPCONSISTING OF AMINOTRIAZINES AND TRIAZONES, DRYING AND THEN HEATING THETREATED AND DRIED FIBERS AT A TEMPERATURE OF AT LEAST 350*F.